High Resolution Studies of Solar Flares, Active Regions and the Quiet Sun at Centimeter and Millimeter Wavelengths

厘米和毫米波长下太阳耀斑、活动区域和安静太阳的高分辨率研究

• 批准号: 9019893
• 负责人: Mukul Kundu
• 金额: $ 44万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-01-15 至 1994-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9019893&HistoricalAwards=false
• 关键词: Resolution; Studies; Solar; Flares; Active

This study will continue investigations of solar radio emissions in the millimeter and centimeter wavelength domain, making use of the Very Large Array (VLA) of the National Radio Astronomy Observatory, and the Berkeley-Illinois-Maryland Millimeter Array (BIMA) at Hat Creek. The observed magnetic structure of sunspot associated microwave sources will be compared with model computations to determine the vertical and horizontal components of the magnetic field at specific locations in the low corona. Along with simultaneous soft X-ray observations, estimates will be made of the electron temperature and emission measure and magnetic field in coronal loops. The VLA microwave data along with Spacelab 2 observations of the transition region and coronal lines will be used to study the temperature and density structure of the sunspot atmosphere in three dimensions. Microwave imaging data will also be compared with hard X-ray burst data to compare the power law index of energetic electrons based on radio and X-ray data, to try to reconcile the two indices through appropriate energization mechanisms. Using VLA observations of flares simultaneously acquired with balloon/rocket borne X-ray and UV measurements, flare physics including the origin of microbursts will be studied. Using BIMA, high spatial resolution studies of flares at millimeter wavelengths will be conducted. In particular, the size and spectra of millimeter burst sources, the problem of electron and proton acceleration in gamma ray/millimeter flares and the anisotropy of these flares will be investigated. The relative timing of mm wave vs. cm wave bursts should help distinguish among the possible causes of the simultaneous flare brightening in H, EUV, and hard X-rays. Observations of filaments at mm and cm wavelengths will also be made to determine the nature of bright lanes (at 15 GHz) spanning filaments, and to determine the density-temperature structure of the transition sheath and coronal cavity. Other proposed studies include mm active regions including their polarization and magnetic fields, mapping of coronal holes and quiet regions such as supergranulation network boundaries at mm wavelengths, and to search for acoustic waves in the chromosphere. ***

这项研究将继续调查太阳射电 毫米和厘米波长域中的发射， 利用国家广播电台的甚大天线阵（VLA） 伯克利-伊利诺伊-马里兰州天文台 帽子溪的毫米波阵列（比马）。 观察到的磁场 太阳黑子相关微波源的结构将 与模型计算结果进行比较， 特定位置的磁场水平分量 在低电晕。 沿着同步软X射线 观测，估计将作出的电子温度 日冕环中的辐射测量和磁场。 的 VLA微波数据沿着空间实验室2号观测， 过渡区和日冕线将被用来研究 年太阳黑子大气的温度和密度结构 三维空间微波成像数据也将进行比较 与硬X射线暴数据进行比较， 基于无线电和X射线数据的高能电子， 通过适当的调整， 机制等 用VLA同时观测耀斑 通过气球/火箭携带的X射线和紫外线测量获得， 耀斑物理学，包括微暴流的起源， 研究了利用比马方法， 毫米波长将被传导。特别是，尺寸 和毫米波爆发源的光谱，电子的问题， 和伽玛射线/毫米耀斑中的质子加速， 将研究这些耀斑的各向异性。 的相对 毫米波与厘米波爆发的时间应有助于区分 在耀斑同时变亮的可能原因中， 在H、EUV和硬X射线中。在mm和mm处观察细丝 cm波长也将被用来确定 明亮的通道（在15 GHz）跨越灯丝，并确定 过渡鞘层的密度-温度结构， 冠状腔 其他拟议的研究包括mm活性 区域，包括其极化和磁场，映射 冕洞和平静区域的存在 在毫米波长的网络边界，并搜索声学 色球层的波动***